Hello I want to get a Bell Racing helmet for my son, he's 9 and races go karts. It needs to be very light and very cooling. Can you please supply me with the weights of this helmet and a few others you have.
For 9 year old you will be better off with the CMR certified helmets as
these are made specifically for children so have low weight as a priority.
The Bell KC3 CMR weighs 1.3kg in size 57cm
The Arai CMR helmet weighs 1.2kg in the size 56cm
The RS7K is not a child specific helmet so is noticeably heavier at
1.6kg in a size 58-59cm:
11th March 2014